In diesel engines and specifically such engines produced by Detroit Diesel, valve rockers in the cylinder head are actuated by a roller cam followers and pushrod arrangements. Cam followers are preloaded by springs that are concentric with pushrods which are held within the cylinder head by snap rings mounted in cooperating grooves. Often these snap rings which are in the form of shaped wire sections or the snap ring grooves are damaged and repair of the grooves or replacement of the rings is necessary. Normally when such a snap ring groove became chipped or cracked, it is necessary to remove the cylinder head from the engine in order to replace it with a new head, which is an expensive and time consuming operation.